Not even a sharp decline in U.S. oil production can convince investors that crude prices are ready to rebound.

Stubbornly high U.S. inventories and resurgent output from OPEC, Russia and Canada have prompted money managers to cut bets on rising prices to the lowest level in four months. West Texas Intermediate crude fell last week even as U.S. government data showed output slid to the least since May 2014.

“The problem is that OPEC more than makes up for every barrel of lost U.S. production,” said Stephen Schork, president of the Schork Group Inc., a consulting company in Villanova, Pennsylvania.

U.S. production tumbled 194,000 barrels a day to 8.43 million in the week ended July 1, an Energy Information Administration report showed. Output has slumped 12 percent from the four-decade peak reached in June 2015. The Organization of Petroleum Exporting Countries boosted production 0.7 percent to 32.9 million barrels a day in June, according to Bloomberg estimates.

WTI fell July 7 after the EIA said U.S. crude supplies shrank by a smaller-than-projected 2.22 million barrels to 524.4 million. Inventories remain at the highest seasonal level in at least a decade. Crude imports averaged 8 million barrels a day in the four weeks ended July 1, up 12 percent from a year earlier.

“While U.S. production looks weak, there's only been a modest decline in U.S. inventories,” said Tim Evans, an energy analyst at Citi Futures Perspective in New York. “The offsetting factor has been very robust imports.”

Money managers cut net long wagers on WTI to the lowest since March in the week ended July 5, according to Commodity Futures Trading Commission data. WTI dropped 2.6 percent to $46.60 a barrel in the report week.

Iranian production has surged 25 percent this year to an average 3.5 million barrels a day, data compiled by Bloomberg show. Iran plans to pump 4 million barrels a day by year-end and reach 4.8 million within five years, Oil Minister Bijan Namdar Zanganeh said June 3 in Vienna.

Russia exported an average 5.55 million barrels a day in the first half of 2016, up 4.9 percent from last year. It pumped 10.84 million barrels a day last month, up 1.1 percent from a year earlier, Energy Ministry data show.

Canadian oil-sands producers are restoring production after the worst wildfires in Alberta's history. Suncor Energy Inc. and Syncrude Canada Ltd. are among the producers that have brought back more than a million barrels a day.

In the Brent market, money managers reduced bullish bets by 14,787 contracts in the week, according to data from ICE Futures Europe. Bets that prices will rise outnumbered short positions by 312,270 lots, the least since February, the London-based exchange said in a report.

The decline in U.S. production might end if drillers keep returning rigs to their fields, according to Rob Haworth, a senior investment strategist in Seattle at U.S. Bank Wealth Management, which oversees $133 billion of assets. The number of active oil rigs in the U.S. has increased in five of the past six weeks, Baker Hughes Inc. data show.

“You have to be worried about the uptick in the rig count and what that will mean for production,” Haworth said. “If this continues, the decline in output will come to an end.”